Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

Various circuit board sockets and methods of manufacturing and using the
same are disclosed. In one aspect, a method of manufacturing is provided
that includes forming a socket that is operable to receive a circuit
board. The socket includes a surface for seating a first portion of a
circuit board, a floor and a first support structure projecting away from
the floor to support a second portion of the circuit board. The support
structure includes a plurality of nested frames. In another aspect, a
socket with a with socket cover coupled to a socket housing is disclosed.
The socket housing includes a support structure to support a portion of
the socket cover.

Claims:

1. A method of mounting a circuit board, comprising: placing the circuit
board in a socket, the socket including a socket cover coupled to a
socket housing, the socket housing having a first surface with plural
cavities and a first support structure projecting away from the first
surface and adapted to support a portion of the socket cover; and
securing the circuit board to the socket.

2. The method of claim 1, wherein the socket cover includes a second
surface for seating a first portion of a circuit board and a second
support structure projecting away from the second surface and adapted to
support the circuit board.

3. The method of claim 2, wherein the socket cover includes a third
surface facing the first surface of the socket housing, the third surface
having a third support structure projecting away from the third surface
and adapted to support the socket cover.

4. The method of claim 2, wherein the second support structure comprises
a first plurality of nested frames.

5. The method of claim 1, wherein the socket cover includes a second
surface facing the first surface of the socket housing and second support
structure projecting away from the second surface and adapted to support
the circuit board.

6. The method of claim 1, wherein the first support structure comprises a
first plurality of nested frames.

7. The method of claim 1, wherein the socket is coupled to another
circuit board.

8. The method of claim 1, wherein the socket cover comprises a floor with
plural socket holes and the circuit board comprises plural conductor pins
to penetrate at least some of the socket holes.

9. The method of claim 1, wherein the socket cover is slidably coupled to
the socket housing, the step of securing the circuit board comprising
sliding the socket cover relative to the socket housing.

10. The method of claim 1, wherein the socket includes a second support
structure projecting away from the first surface and laterally separated
from the first support structure.

11. A method of manufacturing, comprising: forming a socket operable to
receive a circuit board, the socket including a socket cover coupled to a
socket housing, the socket housing having a first surface with plural
cavities and a first support structure projecting away from the first
surface and adapted to support a portion of the socket cover.

12. The method of claim 11, wherein the socket cover includes a second
surface for seating a first portion of a circuit board and a second
support structure projecting away from the second surface and adapted to
support the circuit board.

13. The method of claim 12, wherein the socket cover includes a third
surface facing the first surface of the socket housing, the third surface
having a third support structure projecting away from the third surface
and adapted to support the socket cover.

14. The method of claim 12, wherein the second support structure
comprises a first plurality of nested frames.

15. The method of claim 11, wherein the socket cover includes a second
surface facing the first surface of the socket housing and second support
structure projecting away from the second surface and adapted to support
the circuit board.

16. The method of claim 11, wherein the first support structure comprises
a first plurality of nested frames.

17. The method of claim 11, comprising coupling the socket to another
circuit board.

18. The method of claim 11, wherein the forming the socket comprises
forming a socket housing and a socket cover slidedly mounted on the
socket housing.

20. A method of operating an electronic device, comprising: placing a
circuit board in a socket, the circuit board including a semiconductor
chip electrically connected to the socket, the socket positioned in the
electronic device and including a socket cover coupled to a socket
housing, the socket housing having a first surface with plural cavities
and a first support structure projecting away from the first surface and
adapted to support a portion of the socket cover; and performing
electronic operations with the semiconductor chip.

21. The method of claim 20, wherein the socket is coupled to another
circuit board positioned in the electronic device.

22. An apparatus, comprising: a socket operable to receive a circuit
board, the socket including a socket housing, a socket cover coupled to
the socket housing, the socket housing having a first surface with plural
cavities and a first support structure projecting away from the first
surface and adapted to support a portion of the socket cover.

23. The apparatus of claim 22, wherein the socket cover includes a second
surface for seating a first portion of a circuit board and a second
support structure projecting away from the second surface and adapted to
support the circuit board.

24. The apparatus of claim 23, wherein the socket cover includes a third
surface facing the first surface of the socket housing, the third surface
having a third support structure projecting away from the third surface
and adapted to support the socket cover.

25. The apparatus of claim 23, wherein the second support structure
comprises a first plurality of nested frames.

26. The apparatus of claim 22, wherein the socket cover includes a second
surface facing the first surface of the socket housing and second support
structure projecting away from the second surface and adapted to support
the circuit board.

27. The apparatus of claim 22, wherein the first support structure
comprises a first plurality of nested frames.

28. The apparatus of claim 22, wherein the socket is coupled to another
circuit board.

29. The apparatus of claim 22, wherein the socket cover is slidedly
coupled to the socket housing.

30. The apparatus of claim 22, wherein the circuit board comprises plural
conductor pins and the socket cover comprises a floor with plural socket
holes operable to receive corresponding of the plural conductor pins of
the circuit board.

Description:

[0001] This application is a continuation-in-part of application Ser. No.
12/774,780, filed May 6, 2010.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to semiconductor processing, and
more particularly to sockets useful with, for example, circuit boards,
and to methods of making and using the same.

[0004] 2. Description of the Related Art

[0005] In various types of electronic systems, microprocessors and
sometimes other types of integrated circuits are often connected to some
form of larger printed circuit board, such as a motherboard,
daughterboard or other type of a printed circuit board. In some cases,
the integrated circuit is connected to the motherboard by direct
soldering or other direct mounting techniques. In other cases, a socket
is provided on the upper surface of the motherboard that is designed to
receive the integrated circuit. For those integrated circuits that
consist of some type of package enclosure and some plurality of conductor
pins that project from the package, the motherboard socket includes a
corresponding plurality of individual socket holes that are arranged
spatially to match up with corresponding conductor pins on the integrated
circuit package.

[0006] In one conventional socket design, the integrated circuit socket
consists of a fortress-like structure that has four walls interconnected
at four corners. The four walls enclose an interior space that has a
bottom surface provided with a plurality of the aforementioned individual
socket holes spatially arranged to receive respective conductor pins of
the integrated circuit. When the integrated circuit package is seated in
the socket, structural support for the integrated circuit package is
provided by way of the four corners and the walls of the socket. The
walls of the socket tend to be relatively narrow when compared to the
length and width of the integrated circuit package. Consequently, the
structural support for the integrated circuit package is largely confined
to the four corners of the integrated circuit package as well as a narrow
peripheral band at the edge of the integrated circuit package.

[0007] The lack of a centralized support structure for an integrated
circuit package in a motherboard socket might not present a difficult
problem for integrated circuits if the only downward loads associated
with the integrated circuit package consisted of the weight of the
package itself. However, conventional designs of integrated circuits
frequently require the use of a heatsink of one form or another that is
positioned and held tightly on the integrated circuit package by way of a
clamping mechanism. The application of a downward clamping force on the
integrated circuit package through the heatsink is resisted in the
conventional design described herein by the narrow walls and corners of
the socket. With little or no central support for the integrated circuit
package, the application of the downward clamping force on the heatsink
can result in moments acting upon the integrated circuit package
substrate.

[0008] Conventional ceramic integrated circuit package substrates may have
sufficient stiffness to resist the action of such moments. However, many
currently-available integrated circuit packages utilize a so-called
organic substrate, which consists of one or more laminated layers of
polymer materials. Such polymeric substrates have greater flexibility
than comparably sized ceramic substrates. Thus, an organic substrate may
simply be too flexible to resist the moments associated with the heatsink
clamping force. If an organic substrate undergoes excessive flexure, the
central portion of the organic substrate may warp downward and produce a
tensile loading and an attendant stretching of a thermal interface
material interposed between the integrated circuit package lid and the
enclosed integrated circuit. For those types of thermal interface
materials that utilize a compliant matrix interspersed with aluminum
spheres, the stretching can lead to dramatic increases in the spacing
between individual aluminum spheres. As the spacing between aluminum
spheres increases, the thermal conductivity of the thermal interface
material may drop off and lead to temperature spiking in the integrated
circuit. If the temperature spiking is severe enough, thermal shutdown
may occur.

[0009] One conventional socket design does include four upwardly
projecting pillars that project from the bottom surface of the socket
cover to provide limited and spatially confined structural support for
small areas of a microprocessor package. These pillar supports may be
sufficient for specific die sizes. Another conventional design utilizes a
so-called "tic tac toe" configuration. As the name implies, the
tic-tac-toe configuration utilizes two sets of intersecting walls that
form a tic-tac-toe pattern. The intersecting walls span the entirety of
the socket floor, from one opposing wall of the socket to the other.
Still another conventional design utilizes a centrally positioned mound
that rises from the socket cover floor.

[0010] Conventional sockets of the type just described are often
electrically and physically connected to an underlying circuit board by
way of plural solder balls that are connected to corresponding contacts
within the socket housing and to contact structures or pads on the
circuit board. These ohmic connections are established by a reflow
process that temporarily liquefies the solder balls. One pitfall of
utilizing such solder structures that require a reflow is that the post
reflow state of the socket housing may be warped upward slightly.
Although this warpage may be relatively subtle, resulting in a height
differential between the center and edge of the socket housing on the
order of less than a millimeter or so, the warpage may be enough to
present difficulties. One issue raised is the possibility that package
designers must fabricate conductor pins with long enough lengths to
compensate for the warped socket housing and still establish proper ohmic
contact with the various contacts in the socket housing. Another issue is
that the socket housing may not provide sufficient structural support for
the central portion of the overlying socket cover and in turn the
semiconductor chip package substrate that is seated thereon.

[0011] The present invention is directed to overcoming or reducing the
effects of one or more of the foregoing disadvantages.

SUMMARY OF EMBODIMENTS OF THE INVENTION

[0012] In accordance with one aspect of an embodiment of the present
invention, a method of mounting a circuit board is provided that includes
placing the circuit board in a socket. The socket includes a surface for
seating a first portion of the circuit board, a floor and a first support
structure projecting away from the floor to support a second portion of
the circuit board. The first support structure includes a first plurality
of nested frames. The circuit board is secured to the socket.

[0013] In accordance with another aspect of an embodiment of the present
invention, a method of manufacturing is provided that includes forming a
socket that is operable to receive a circuit board. The socket includes a
surface for seating a first portion of a circuit board, a floor and a
first support structure projecting away from the floor to support a
second portion of the circuit board. The support structure includes a
first plurality of nested frames.

[0014] In accordance with another aspect of an embodiment of the present
invention, a method of operating an electronic device is provided that
includes placing a circuit board in a socket. The circuit board includes
a semiconductor chip electrically connected to the socket. The socket is
positioned in the electronic device and includes a surface for seating a
first portion of the circuit board, a floor and a first support structure
projecting away from the floor to support a second portion of the circuit
board. The first support structure includes a first plurality of nested
frames. Electronic operations are performed with the semiconductor chip.

[0015] In accordance with another aspect of an embodiment of the present
invention, an apparatus is provided that includes a socket operable to
receive a circuit board. The socket includes a surface for seating a
first portion of the circuit board, a floor and a first support structure
projecting away from the floor to support a second portion of the circuit
board. The first support structure includes a first plurality of nested
frames.

[0016] In accordance with another aspect of an embodiment of the present
invention, a method of mounting a circuit board is provided that includes
placing the circuit board in a socket. The socket includes a socket cover
coupled to a socket housing. The socket housing has a first surface with
plural cavities and a first support structure projecting away from the
first surface and adapted to support a portion of the socket cover. The
circuit board is secured to the socket.

[0017] In accordance with another aspect of an embodiment of the present
invention, a method of manufacturing is provided that includes forming a
socket operable to receive a circuit board. The socket includes a socket
cover coupled to a socket housing. The socket housing has a first surface
with plural cavities and a first support structure projecting away from
the first surface and adapted to support a portion of the socket cover.

[0018] In accordance with another aspect of an embodiment of the present
invention, a method of operating an electronic device is provided that
includes placing a circuit board in a socket. The circuit board includes
a semiconductor chip electrically connected to the socket. The socket is
positioned in the electronic device and includes a socket cover coupled
to a socket housing. The socket housing has a first surface with plural
cavities and a first support structure projecting away from the first
surface and adapted to support a portion of the socket cover. Electronic
operations are performed with the semiconductor chip.

[0019] In accordance with another aspect of an embodiment of the present
invention, an apparatus is provided that includes a socket operable to
receive a circuit board. The socket includes a socket housing and a
socket cover coupled to the socket housing. The socket housing has a
first surface with plural cavities and a first support structure
projecting away from the first surface and adapted to support a portion
of the socket cover.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The foregoing and other advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the drawings in which:

[0021] FIG. 1 is a pictorial view of an exemplary embodiment of a circuit
board that includes a socket suitable to receive a semiconductor chip
device;

[0022] FIG. 2 is a plan view of the exemplary circuit board depicted in
FIG. 1;

[0023] FIG. 3 is a sectional view of FIG. 2 taken at section 3-3;

[0024]FIG. 4 is a plan view like FIG. 2, but of an alternate exemplary
circuit board and socket;

[0025]FIG. 5 is a pictorial view of another alternate exemplary circuit
board with a socket suitable to receive a semiconductor chip device;

[0026] FIG. 6 is a pictorial view of another alternate exemplary circuit
board with a socket suitable to receive a semiconductor chip device;

[0027]FIG. 7 is a pictorial view of another alternate exemplary circuit
board with a socket suitable to receive a semiconductor chip device and
with a socket housing support structure;

[0028]FIG. 8 is a plan view of the alternate exemplary socket of FIG. 7;

[0030]FIG. 10 is a simplified sectional view like FIG. 9, but without
cross-hatching;

[0031]FIG. 11 is a plan view of another alternate exemplary circuit board
with a socket suitable to receive a semiconductor chip device and with
socket housing support structures;

[0032]FIG. 12 is a sectional view like FIG. 9, but of another alternate
exemplary circuit board with a socket suitable to receive a semiconductor
chip device and with a socket housing support structure and a socket
cover support structure;

[0033]FIG. 13 is a sectional view like FIG. 12, but of another alternate
exemplary circuit board with a socket suitable to receive a semiconductor
chip device and with a socket housing support structure and an alternate
exemplary socket cover support structure;

[0034]FIG. 14 is a pictorial view of another alternate exemplary circuit
board with a socket suitable to receive a semiconductor chip device and
with alternative socket housing support structures;

[0035]FIG. 15 is a schematic depiction of an exemplary molding process
that may be used to fabricate any of the disclosed sockets;

[0036] FIG. 16 is an exploded pictorial view of an exemplary circuit board
mounted to an electronic device; and

[0037] FIG. 17 is a flow chart depicting exemplary steps of using an
exemplary socket and semiconductor chip device to perform electronic
operations.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0038] Various sockets useful with, for example, circuit boards are
disclosed. In one aspect, a socket is disclosed that is operable to be
mounted on a circuit board and, in-turn, receive a semiconductor chip
device, such as a semiconductor chip package. The socket includes a cover
with an opening leading to a floor. The floor includes a support
structure that projects away from the floor to support a portion of the
semiconductor chip device. In one embodiment, the support structure
includes plural nested frames. In another aspect, a socket with a socket
cover coupled to a socket housing is disclosed. The socket housing
includes a support structure to support a portion of the socket cover.
Additional details will now be described.

[0039] In the drawings described below, reference numerals are generally
repeated where identical elements appear in more than one figure. Turning
now to the drawings, and in particular to FIG. 1 therein is depicted a
pictorial view of an exemplary embodiment of a circuit board 10 that
includes a socket 15 that is suitable to receive a semiconductor chip
device 20, which is shown exploded. The semiconductor chip device 20 may
include one or more semiconductor chips 22 mounted on a circuit board 24,
and may be fitted with a suitable heat spreader or lid 25 as desired. The
lid 25 is shown exploded from the circuit board 24. To facilitate heat
transfer from the semiconductor chip 22 to the lid 25 a thermal interface
material 27 may be applied to the semiconductor chip 22, to an underside
of the lid 25 or both. The circuit board 10 includes a substrate 30 upon
which the socket 15 and various other devices, such as semiconductor chip
packages 32, passive devices 33, and may include other sockets (not
shown) or any of the myriads of types of circuit elements that may be put
on a circuit board.

[0040] The socket 15 may be used as an interface for a myriad of different
types of circuit boards and semiconductor chips. For example, the circuit
board 24 may be a semiconductor chip package substrate, a circuit card, a
pinned socket adapter, or virtually any other type of printed circuit
board. Although a monolithic structure could be used for the circuit
board 24, a more typical configuration will utilize a build-up design. In
this regard, the circuit board 24 may consist of a central core upon
which one or more build-up layers are formed and below which an
additional one or more build-up layers are formed. The core itself may
consist of a stack of one or more layers. If implemented as a
semiconductor chip package substrate, the number of layers in the circuit
board 24 can vary from four to sixteen or more, although less than four
may be used. So-called "coreless" designs may be used as well. The layers
of the circuit board 24 may consist of an insulating material, such as
various well-known epoxies, interspersed with metal interconnects. A
multi-layer configuration other than buildup could be used. Optionally,
the circuit board 24 may be composed of well-known ceramics or other
materials suitable for package substrates or other printed circuit
boards. The circuit board 24 may be provided with a number of conductor
traces and vias and other structures (not visible) in order to provide
power, ground and signals transfers between the semiconductor chip 22 and
another device, such as the socket 15 for example. In this illustrative
embodiment, the circuit board 24 includes conductor pins 34 connected to
the latent traces and vias.

[0041] The semiconductor chip 22 may be any of a large number of different
types of circuit devices used in electronics, such as, for example,
microprocessors, graphics processors, combined microprocessor/graphics
processors, application specific integrated circuits, memory devices or
the like, and may be single or multi-core or even stacked with or
accompanied by additional dice. The semiconductor chip 22 may be
constructed of bulk semiconductor, such as silicon or germanium, or
semiconductor-on-insulator materials, such as silicon-on-insulator
materials.

[0042] The circuit board substrate 30 may be a motherboard, a circuit
card, a semiconductor chip package substrate or virtually any other type
of printed circuit board. Structurally speaking, the circuit board
substrate 30 may use the same types of structures and materials as the
circuit board 24.

[0043] The optional lid 25 may be a bath tub design as depicted, a top hat
design or some other configuration as desired. The lid 25 may be composed
of well-known ceramics or metallic materials as desired. Some exemplary
materials include nickel plated copper, anodized aluminum,
aluminum-silicon-carbon, aluminum nitride, boron nitride or the like. The
lid 25 may be secured to the substrate 24 by an adhesive composed of a
well-known thixotropic adhesive, an epoxy, another type of polymer or
even a solder.

[0044] In this illustrative embodiment, the socket 15 is a pin grid type
socket that includes a housing 35 mounted on the substrate 30 and a
socket cover 45 that is slidedly mounted on the socket housing 35. The
sliding movement of the socket cover 45 relative to the socket housing 35
is facilitated by a swingable lever arm 50 that is connected to a cam or
other type of mechanism (not shown) suitable to provide sliding movement
of the cover 45 relative to the housing 35. Here, the lever 50 is shown
in a locked down position and restrained laterally by way of a retaining
latch 55 that may be attached to the socket housing 35. The socket cover
45 is provided with an internal opening 60 that terminates vertically in
a floor 65. The floor 65 is provided with a plurality of socket holes 70,
which are designed to receive corresponding pins 34 of the circuit board
24. As described more fully below, the socket holes 70 lead through the
socket cover 45 and provide access for the pins 34 to conducting
structures (not visible) that are mounted in the socket housing 35. The
upper surface of the socket cover 45, and in particular the portions 80a,
80b, 80c and 80d, provides a seating surface to support the edges 85a,
85b, 85c and 85d of the circuit board 24 of the semiconductor chip device
20.

[0045] The circuit board 20 may be subjected to significant stresses in
the z-axis direction. These may be caused by various mechanisms, such as
temperature induced warping of the substrate 24 and forces transmitted
down by the lid 25 when a heat sink (not shown) is tightly clamped down
on the lid 25. If the portion of the substrate 24 that supports the
semiconductor chip 22 is not, in-turn, sufficiently supported, then large
z-axis strains could harm the semiconductor chip 22 or cause undesired
stretching of the thermal interface material 27. To provide the desired
support, the socket cover 45 is provided with a support structure 90,
which in this illustrative embodiment, may consist of a plurality of
nested frames. As depicted in more detail in FIG. 3, the support
structure 90 advantageously has a vertical dimension along a z-axis that
is just slightly higher than the distance along the same axis from the
floor 65 to the support surfaces 80a, 80b, 80c and 80d. In this way, the
central portion 98 of the semiconductor chip device 20, particularly in
the vicinity of the semiconductor chip 22, is adequately supported when
the semiconductor chip device 20 is seated in the socket cover 45.

[0046] Additional details of the circuit board 10 and the socket 15 may be
understood by referring now to FIG. 2, which is a plan view of the
circuit board 10 and the socket 15 but without the semiconductor chip
device 20 or the lid 25 depicted in FIG. 1 in place. Here, the socket
housing 35, the socket cover 45, the lever arm 50 and the retaining latch
55 are clearly visible. In this illustrative embodiment, the opening 60
of the socket cover 45 may be generally octagonal as shown. However, the
skilled artisan will appreciate that many other shapes may be used. In
this illustrative embodiment, the support structure 90 may consist of
seven nested frames that are sized and shaped of decreasing footprint so
that the space along either an x or y axis between two adjacent frames
may be occupied by a single row of the socket holes 70. However, the
skilled artisan will appreciate that the number of frames may be other
than seven and the spacing between adjacent frames may be such that
multiple socket holes may be straddled therebetween. The support
structure 90 in this illustrative embodiment has a rectangular footprint
that may be defined by the dimensions x1 and y1. A technical
goal of the embodiments disclosed herein is to provide the support
structure 90 with a footprint defined perhaps by the dimensions x1
and y1 that corresponds roughly to the footprint of the
semiconductor chip 22 of the semiconductor chip device 20 depicted in
FIG. 1. However, shapes other than rectangular are envisioned and the
nested frames need not be concentric. Furthermore, and as shown in a
subsequent illustrative embodiment, multiple support structures may be
provided in order to support multiple areas of a seated circuit board,
which may be useful in circumstances where a semiconductor chip device
includes multiple chips separated laterally on a carrier substrate or for
other types of devices that would require vertical support. In this
illustrative embodiment, the pitch along the x-axis and the y-axis
between adjacent of the socket holes 70 is relatively constant. However,
the skilled artisan will appreciate that the arrangement of socket holes
70 may be nonuniform in that a variety of different pitches may be used
and entire areas of the floor 65 of the socket cover 45 may be devoid of
socket holes 70 as desired.

[0047] The socket housing 35 and the socket cover 45 may be composed of a
variety of electrically insulating materials, such as liquid crystal
polymer, fiberglass resin materials, well-known plastics or the like. The
support structure 90 is advantageously composed of the same materials
used to fabricate the socket cover 45 and in this way may be fabricated
by molding or otherwise at the same time as the socket cover 45.
Optionally, the support structure 90 could be separately fabricated from
the same or another type of insulating material and thereafter secured to
the floor 65 of the socket cover 45 by adhesives or other fastening
techniques.

[0048] Still further details of the socket cover 45 may be understood by
referring now to FIG.

[0049] 3, which is a sectional view of FIG. 2 taken at section 3-3. Note
that section 3-3 passes through three of the nested frames of the support
structure 90 as well as several of the socket holes 70 but only passes
through a portion of the supporting surface 80d and does not encompass
the entirety of the floor 65 of the socket cover 45. Here, the three
visible nested frames of the support structure 90 are shown and labeled
100a, 100b and 100c, respectively. Note that the support structure 90 or
at least some of the nested frames 100a, 100b and 100c, etc. thereof
project slightly above the support surfaces 80d and 80a of the socket
cover 45. This height differential between the support structure 90 and
the support surfaces 80a, 80b, 80c and 80d of the socket cover 45 may
take on a variety of values. In an exemplary embodiment, the depth d of
the opening 60 may be about 0.3 mm and the height differential between
the depth d and the amount that the support structure 90 projects above
the support surfaces 80a, 80b, 80c and 80d may be about 0.05 mm. In this
way, the support structure 90 can provide a supporting framework that has
approximately the same footprint as the central portion of the circuit
board 20 or at least the semiconductor chip 22 while still providing easy
access for the pins 75. Still referring to FIG. 3, when the circuit board
24 of the semiconductor chip device 20 is seated in the socket cover 45,
the pins 75 project downward into corresponding of the socket holes 70.
After seating, the pins 75 project into the holes 70 and the socket cover
45 is moved along the x-axis relative to the socket housing 35 in order
to bring the pins 75 into engagement with corresponding conductor
terminals 110 that are positioned in respective spaces 115 in the socket
housing 35. The terminals 110 may be connected to corresponding solder
balls 120 or other conductor structures that connect the socket housing
35 to the circuit board 10. The skilled artisan will appreciate that the
types of conductor structures used to make contact with the pins 75 as
well as the circuit board 10 may take on a huge variety of different
configurations.

[0050] An alternate exemplary embodiment of a socket 415 that may be used
with a circuit board 410 may be understood by referring now to FIG. 4,
which is a plan view like FIG. 2. In this illustrative embodiment, the
socket 415 may include a socket housing 435 that supports a socket cover
445. Like the other embodiments disclosed herein, the socket cover 445
may be movable along an x-axis relative to the socket housing 435 by way
of a cam or other mechanism (not visible) operated by the depicted lever
450 that may seat in a retaining latch 455 as desired and described
elsewhere herein. Of course, other types of mechanisms may be used to
establish the requisite relative movement between the socket cover 445
and the socket housing 435. Furthermore, as is the case for any of the
disclosed embodiments, there need not be any relative motion between the
socket cover 445 and the socket housing 435, particularly if such
movement is not required in order to establish contact between whatever
interconnects are used for the circuit board that seats in the socket 415
and the mating conductor structures in the socket housing 435. Here, the
socket cover 445 includes an opening 460 that leads to a floor 465
populated by socket holes 470 that may be arranged as described elsewhere
herein. However, in this illustrative embodiment, two support structures
490a and 490b may be provided on the floor 465 in order to support
multiple portions of a circuit board or other structure that is seated in
the socket cover 445. As noted elsewhere herein, this arrangement may be
useful in circumstances where the circuit board to be seated in the
socket cover 445 includes two spaced-apart semiconductor chips each
requiring separate supporting elements or some other configuration that
calls for separate and discrete supporting elements. Again, the number of
nested frames that make up the support structures 490a and 490b as well
as their geometries are subject to great variety.

[0051] In the foregoing illustrative embodiments, the relative movement
between a socket cover and a socket housing is facilitated by a cam
mechanism that is actuated by way of a lever, such as the lever 50
depicted in FIGS. 1 and 2 and the lever 450 depicted in FIG. 4. However,
the skilled artisan will appreciate that other mechanisms may be used to
actuate a cam or other mechanism to facilitate sliding movement between
two cooperating elements. In this regard, attention is now turned to FIG.
5, which is a pictorial view of a circuit board 510 that includes a
socket 515 that may be configured as generally described elsewhere herein
and depicted in FIGS. 1-4. In this regard, the socket 515 may include a
socket housing 535 and a socket cover 545 is slidedly mounted thereon.
The socket cover 545 may include an opening 560 that leads to a socket
floor 565 populated with plural socket holes 570, and a support structure
590. However, in order to facilitate the sliding movement, a screw head
593 may be secured to a cam mechanism (not shown) beneath the visible
surface of the socket cover 545. By turning the screw head 593 as
suggested by the arrow 594, the socket cover 545 may be moved along the
x-axis relative the socket housing 535 in order to engage whatever
interconnects that project downwardly from a circuit board (not shown) to
be seated in the socket cover 545. Such a screw-activated mechanism may
be suitable in circumstances where the electronic device in which the
circuit board 510 is mounted is relatively small and lacks sufficient
clearance for the positioning and movement of a lever arm or other larger
type of device that requires greater freedom of movement in order to
operate. Any of the disclosed embodiments may use this type of movement
mechanism.

[0052] In the foregoing illustrative embodiments, the sockets 15, 415 and
515 are generally configured to receive a pin interconnect type of
circuit board, such as a pin grid array circuit board. However, the
skilled artisan will appreciate that the utilization of a frame-like
support structure may be tailored for something other than a pin type
socket. For example, a land grid array type of socket may be used. In
this regard, attention is now turned to FIG. 6, which is a pictorial view
of an alternate exemplary embodiment of a circuit board 610 that includes
a socket 615 suitable to receive a semiconductor chip device 620 that may
be configured like the semiconductor chip device 20, but with a land grid
array for input/output. In this regard, the socket 615 may include a
socket housing 635 and a socket cover 645 that is not movable relative to
the socket housing 635. Indeed, the socket cover 645 could be formed
integrally with the socket housing 635 as desired. The socket cover 645
includes an opening 660 that leads to a floor 665. The floor 665 may be
populated by a land grid array 695 that consists of a plurality of
compressible contacts that are conductive elements used to establish
ohmic contact with a corresponding set of lands (not visible) of the
semiconductor chip device 620. Here, a support structure, such as the
support structure 690, may be interspersed among the lands of the array
695 and used to support the semiconductor chip device 620 as disclosed
generally herein. However, some other type of mechanism may be used to
secure the semiconductor chip device 620 to the socket cover 645. In this
regard, and in this illustrative embodiment, a hinge operated clamping
frame 696 may be used to secure the semiconductor chip device 620 to the
socket cover 645 following seating thereon. The skilled artisan will
appreciate that many different types of fastening mechanisms may be used
other than the clamping frame 696 as desired. Of course, it should be
appreciated that any of the disclosed embodiments of a socket 15, 415,
515 and 615, and those to be described, could use gravity alone to seat a
circuit board thereon.

[0053]FIG. 7 is a pictorial view of an alternate exemplary embodiment of
a circuit board 710 that includes a socket 715 suitable to receive the
semiconductor chip device 20. Here the semiconductor chip device 20 is
shown with the circuit board 24 and the lid 25 joined, but otherwise
exploded from the socket 715 and with conductor pins 34 visible. The
circuit board 710 includes the substrate 730 with the socket 715 and
various other devices, such as semiconductor chip packages 32 and passive
devices 33, mounted thereon and may include other sockets (not shown) or
any of the myriads of types of circuit elements that may be put on a
circuit board. The socket 715 may be a pin grid type socket that includes
a housing 735 mounted on the substrate 730 of the circuit board 710 and a
socket cover 745 that is slidedly mounted on the socket housing 735. The
sliding movement of the socket cover 745 relative to the socket housing
735 is facilitated by a swingable lever arm 750 that is connected to a
cam or other type of mechanism (not shown) suitable to provide sliding
movement of the cover 745 relative to the housing 735. Here, the lever
750 is shown in a locked down position and restrained laterally by way of
a retaining tab 757 that may be attached to the socket cover 745.
Furthermore, as is the case for any of the disclosed embodiments, there
need not be any relative motion between the socket cover 745 and the
socket housing 735, particularly if such movement is not required in
order to establish ohmic contact between whatever interconnects are used
for the circuit board 24 that seats in the socket 715 and the mating
conductor structures in the socket housing 735. The socket cover 745 is
provided with an internal opening 760 that terminates vertically in a
floor 765. The floor 765 is provided with a plurality of socket holes
770, which are designed to receive corresponding pins 34 of the circuit
board 24. As described more fully below, the socket holes 770 lead
through the socket cover 745 and provide access for the pins 34 to
conducting structures (not visible) that are mounted in the socket
housing 735. The upper surface 762 of the socket cover 745, and in
particular the portions 780a, 780b, 780c and 780d, provides a seating
surface to support the edges 85a, 85b, 85c and 85d of the circuit board
24 of the semiconductor chip device 20. The socket housing 735 and socket
cover 745 may be substantially identical structurally to, for example,
the socket depicted in FIG. 1 and described elsewhere herein. There may
be a few structural differences such as the enlarged portion 782 of the
socket cover 745 from which the lever arm 750 projects as well as the
overhanging nature of the socket cover 745 relative to the socket housing
735. However, in terms of basic sliding functionality, the socket housing
735 and socket cover 745 function like the other embodiments disclosed
herein.

[0054] Additional details of the socket may be understood by referring now
also to FIG. 8, which is an enlarged overhead view of the socket depicted
in FIG. 7 but with a central portion of the floor 765 of the socket cover
745 cut away to reveal a portion of an upper surface 783 of the socket
housing 735. Note of course that the upper surface 783 of the socket
housing 735 includes plural cavities 785 that are somewhat aligned
vertically with the pin holes 770 of the socket cover 745. Note also that
in this alternate embodiment, a support structure 787 is provided on the
upper surface 783 of the socket housing 735 that is designed to provide
support for the socket cover 745 following a solder reflow process to
mount the socket 715 to the circuit board 710. Here, the support
structure 787 has the same general configuration as the support structure
90 projecting upward from the socket cover 45 depicted in FIGS. 1 and 2.
Thus, a plurality of nested frames may be used that project upwardly out
of the page. In this illustrative embodiment, the opening 760 of the
socket cover 745 may be generally octagonal as shown. However, the
skilled artisan will appreciate that many other shapes may be used. In
this illustrative embodiment, the support structure 787 may consist of
seven nested frames that are sized and shaped of decreasing footprint so
that the space along either an x or y axis between two adjacent frames
may be occupied by a single row of the cavities 785. However, the skilled
artisan will appreciate that the number of frames may be other than seven
and the spacing between adjacent frames may be such that multiple socket
holes may be straddled therebetween. The support structure 787 in this
illustrative embodiment has a rectangular footprint that may be defined
by the dimensions x1 and y1.

[0055] Still more details of the socket 710 may be understood by referring
now also to FIG. 9, which is an enlarged sectional view of FIG. 8 taken
at section 9-9. Note that section 9-9 passes through the support
structure 787 but only through portions of the socket cover 745 and the
socket housing 735. Note also that FIG. 9 will not depict the cut away of
the socket cover 745 depicted in FIG. 8 but will depict the semiconductor
chip device 20 exploded from the socket 715. The support structure 787 as
noted above includes a plurality of nested frames 789a, 789b, 789c, 789d,
789e, 789f and 789g that are designed to bear against and support, if
necessary, the socket cover 745, and particularly the spaces of the
socket cover 745 between the pin holes 770. Note that the elevations of
the frames 789a, 789b, 789c, 789d, 789e, 789f and 789g of the support
structure 787 may be stratified in that the innermost frame 789a may have
a higher elevation than the outermost frame 789g for example. Since a
technical goal of the support structure 787 to provide a somewhat planar
bearing surface for the socket cover 745 after the socket housing 735 has
undergone an upward warpage during reflow of the solder balls 796, the
outermost frame 789g will by definition be at a higher elevation due to
the warpage than the innermost frame 789a and thus need not have the same
free state elevation as depicted in FIG. 9.

[0056] The supporting function of the support structure post solder reflow
and thus in a warped state may be understood by referring now to FIG. 10,
which is a simplified sectional view like FIG. 9 but without
crosshatching or other features for simplicity of illustration. Here, the
socket housing 735 is shown in a post solder reflow warped condition as
clearly suggested by some of the stretched solder balls 796. Note that
the amount of warpage is exaggerated for ease of visibility. Note also
that the individual frames loops or shells are depicted in a simplified
manner relative to FIG. 9. However, FIG. 10 shows that despite the upward
warpage of the socket housing 735, the frames of the support structure
787 provides a somewhat planar support surface for the socket cover 745,
which provides a better seating surface for the semiconductor device 20.

[0057] Another alternate exemplary embodiment of a socket 1115 may be
understood by referring now to FIG. 11, which is a plan view. Here, the
socket 1115 may be mounted on a circuit board 1110 configured
substantially identically like the socket 715 depicted in FIGS. 7, 8 and
9. However, the socket housing surface 1183 may include plural
spaced-apart support structures 1187a and 1187b that may each be like the
support structure 787 depicted in FIGS. 7, 8 and 9 but separated
laterally as depicted. Such support structures 1187a and 1187b may number
more than two and be arranged in a variety of ways on the socket housing
surface 1183.

[0058] The skilled artisan will appreciate that it may be possible to
combine support structures on both a socket housing and a socket cover on
a circuit board 1210. For example, and as shown in FIG. 12, which is a
sectional view like FIG. 9, an alternate exemplary socket 1215 may
include a support structure 1287 configured like the aforementioned
support structure 1187 in the socket housing 1235 well as a support
structure 1290 configured like the support structure 90 depicted in FIGS.
1 and 2 (or any disclosed alternatives) and described elsewhere herein.

[0059] In still another alternate exemplary embodiment, a circuit board
1310 may include a socket 1315 that has both a support structure 1387
projecting from the socket housing 1335 as well as a support structure
1397 projecting downwardly from the socket cover 1345. In this way, extra
support is provided to restrain a downward warpage of the socket cover
1345 and to provide a relatively planar bearing surface in the event that
the socket housing 1335 undergoes an upward warpage following reflow of
the solder balls 1396.

[0060] As noted elsewhere herein, a variety of different types of
structures may be used for socket supporting structures. In the foregoing
illustrative embodiments, plural nested frames are one disclosed
alternative. However, other than nested frames may be used for either
socket cover or socket housing or both. In this regard, attention is now
turned to FIG. 14, which is a pictorial view of a small portion of a
circuit board 1410, shown only in dashed for simplicity of illustration,
and a small portion of an alternate exemplary socket 1415. In particular,
a small portion of the upper surface 1483 of the socket 1415 is depicted,
which corresponds structurally to, for example, the surface 783 of the
socket 715 as disclosed in FIG. 7. Thus, a few of the cavities 1470 that
lead to underlying conductor structures (not visible) are illustrated.
Here, in lieu of nested frames for support, plural upwardly projecting
members may be used. Two of the members are labeled 1489a and 1489b. The
members 1489a may have a generally rectangular footprint and the members
1489b may have a generally circular footprint. However, some or all of
the structures 1489a and 1489b may be rectangular or circular as desired.
Of course, other footprints are possible. In addition, the members 1489a
and 1489b may have stratified heights as shown to provide the same type
of relatively planar post-warpage support surface for a socket cover (not
visible) as described generally elsewhere herein for the other disclosed
embodiments. The support members 1489a and 1489b may be composed of the
same materials used to fabricate the surface 1483 or be separately
fabricated of the same or other materials and thereafter secured to the
surface 1483 by adhesives or other fastening techniques.

[0061] A variety of techniques may be used to manufacture the socket
housing and socket cover for any of the disclosed embodiments. An example
using the socket housing 1235 and socket cover 1245 depicted in FIG. 12
may be understood by referring now to FIG. 15. A suitable mold 1551 may
be injected with a moldable material 1552 by way of an applicator 1551 or
by way of supply and return lines 1556 and 1558 in order to create, for
example, the socket housing 1235 and the socket cover 1245. Discrete
molding processes may be used for each. The molding process may be
thermoplastic, thermosetting or some other process. Vacuum conditions may
be desirable to enhance structural uniformity. Optionally, machining or
other well-known material shaping techniques could be used.

[0062] Any of the disclosed embodiments of a circuit board, such as
circuit boards 10, 710, 1110, 1210, 1310 or 1410, may be coupled to an
electronic device. FIG. 16 depicts a pictorial view of the circuit board
10 with the socket 15, the semiconductor chip device 20 and semiconductor
chip 22 inserted into a schematically represented electronic device 1665.
Here, the electronic device 1665 may be a computer, a server, a hand held
device, or virtually any other electronic component. The circuit board 10
may be fitted in the electronic device 1665 and secured thereto by
screws, rivets, clamps, adhesives or any other available fastening
method. The semiconductor chip device 20 may be seated therein as
disclosed generally herein. As shown in FIG. 17, at step 1770 the
semiconductor chip device 20 may be mounted to the socket 15 in an
electronic device. At step 1775, electronic operations may be performed
by the semiconductor chip device 20 and the semiconductor chip 22. The
electronic operations may be virtually any operations performed by
integrated circuits.

[0063] While the invention may be susceptible to various modifications and
alternative forms, specific embodiments have been shown by way of example
in the drawings and have been described in detail herein. However, it
should be understood that the invention is not intended to be limited to
the particular forms disclosed. Rather, the invention is to cover all
modifications, equivalents and alternatives falling within the spirit and
scope of the invention as defined by the following appended claims.